Effect of oxalic acid application on Samar Bahisht Chaunsa mango during ripening and postharvest

Abstract

Oxalic acid (OA) is a natural antioxidant delays the ripening and senescence in various fruits. Therefore, ‘Samar Bahisht Chaunsa’ mango fruit were dipped in different concentrations of OA (0, 1, 3 or 5 mmol/L) and allowed to ripen at 32 ± 3 °C for 7 days or stored at 12 ± 1 °C for 28 days. Exogenous application of OA (5 mmol/L) reduced ethylene production, respiration rate and activity of exo-polygalacturonase (exo-PG) enzyme; while, maintained higher fruit firmness and pectin esterase (PE) activity in mango fruit during ripening and cold storage period. OA-treated (5 mmol/L) fruit exhibited higher activities of catalase (CAT), peroxidase (POX) and superoxide dismutase (SOD) enzymes with more total phenolics and antioxidant contents during ripening and cold storage. Postharvest application of OA lowered the SSC contents and SSC:TA ratio; while, TA and ascorbic acid contents were higher in treated fruit throughout the ripening as well as in cold storage period. In conclusion, OA application effectively reduced fruit softening and activity of exo-PG enzyme with enhanced activities of antioxidative enzymes (CAT, POX and SOD) during ripening at ambient conditions and in cold storage.